sensors Mode-S transponder
A2A915
ICAO 24-bit transponder address · allocated to United States
Currently assigned to N27015 · BOEING 777-200 · operated by UNITED AIRLINES INC
- Hex
- A2A915
- Octal
- 50524425
- Decimal
- 10,660,117
- Country
- US
- Tail
- N27015
- Type
- B772
- Flights observed
- 39
- Distinct callsigns
- 17
- Country
- US
- Last broadcast
- 24d ago
Last known position
Country allocation
The ICAO 24-bit address A2A915 falls within the block assigned to United States (US) by ICAO Annex 10, Volume III. Every aircraft registered in United States receives a permanent address from this block at the time of registration; the address stays with the airframe even if the aircraft is re-registered to a different operator within the country.
Callsign history 17 distinct
| Callsign | Airline | Flights | Last seen |
|---|---|---|---|
| UAL918 | United Airlines | 5 | 2026-04-18 |
| UAL804 | - | 5 | 2026-04-13 |
| UAL875 | United Airlines | 4 | 2026-04-13 |
| UAL889 | United Airlines | 3 | 2026-04-28 |
| UAL879 | United Airlines | 3 | 2026-04-19 |
| UAL852 | United Airlines | 3 | 2026-04-23 |
| UAL926 | United Airlines | 2 | 2026-04-29 |
| UAL888 | United Airlines | 2 | 2026-04-27 |
| UAL880 | United Airlines | 2 | 2026-04-18 |
| UAL853 | United Airlines | 2 | 2026-04-22 |
| UAL102 | United Airlines | 2 | 2026-04-19 |
| UAL949 | United Airlines | 1 | 2026-04-21 |
| UAL948 | United Airlines | 1 | 2026-04-21 |
| UAL917 | United Airlines | 1 | 2026-04-26 |
| UAL916 | United Airlines | 1 | 2026-04-27 |
| UAL3860 | United Airlines | 1 | 2026-05-05 |
| UAL195 | United Airlines | 1 | 2026-04-20 |
Recent flights last 39
| Date | Flight | Route | Takeoff | Landing | Duration |
|---|---|---|---|---|---|
| 2026-05-05 | UAL3860 | DEN → IAH | May 5, 12:25 UTC | May 5, 22:40 UTC | 10h 15m |
| 2026-04-29 | UAL926 | SFO → FRA | Apr 29, 02:44 UTC | Apr 29, 13:10 UTC | 10h 26m |
| 2026-04-29 | UAL926 | SFO → FRA | Apr 29, 02:35 UTC | Apr 29, 05:15 UTC | 2h 40m |
| 2026-04-28 | UAL889 | PEK → SFO | Apr 28, 10:45 UTC | Apr 28, 20:55 UTC | 10h 10m |
| 2026-04-27 | UAL888 | SFO → PEK | Apr 27, 17:40 UTC | Apr 28, 05:45 UTC | 12h 5m |
| 2026-04-27 | UAL916 | AKL → SFO | Apr 27, 02:05 UTC | Apr 27, 13:40 UTC | 11h 35m |
| 2026-04-26 | UAL917 | SFO → AKL | Apr 26, 06:15 UTC | Apr 26, 19:05 UTC | 12h 50m |
| 2026-04-25 | UAL889 | PEK → SFO | Apr 25, 09:51 UTC | Apr 25, 20:39 UTC | 10h 48m |
| 2026-04-25 | UAL889 | PEK → SFO | Apr 25, 09:51 UTC | Apr 25, 20:39 UTC | 10h 48m |
| 2026-04-24 | UAL888 | SFO → PEK | Apr 24, 17:50 UTC | Apr 25, 12:30 UTC | 18h 40m |
| 2026-04-23 | UAL852 | TPE → SAN | Apr 23, 08:50 UTC | Apr 23, 09:35 UTC | 45m |
| 2026-04-23 | UAL852 | TPE → SAN | Apr 23, 06:55 UTC | Apr 23, 07:10 UTC | 15m |
| 2026-04-23 | UAL852 | TPE → SAN | Apr 23, 06:51 UTC | Apr 23, 17:36 UTC | 10h 45m |
| 2026-04-22 | UAL853 | SFO → TPE | Apr 22, 21:00 UTC | Apr 22, 21:20 UTC | 20m |
| 2026-04-22 | UAL853 | SFO → TPE | Apr 22, 07:35 UTC | Apr 22, 19:05 UTC | 11h 30m |
| 2026-04-21 | UAL949 | LHR → SFO | Apr 21, 12:30 UTC | Apr 21, 22:55 UTC | 10h 25m |
| 2026-04-21 | UAL948 | SFO → LHR | Apr 21, 00:05 UTC | Apr 21, 10:15 UTC | 10h 10m |
| 2026-04-20 | UAL195 | MUC → SFO | Apr 20, 10:00 UTC | Apr 20, 21:40 UTC | 11h 40m |
| 2026-04-19 | UAL102 | IAH → MUC | Apr 19, 22:00 UTC | Apr 20, 07:40 UTC | 9h 40m |
| 2026-04-19 | UAL102 | IAH → MUC | Apr 19, 22:07 UTC | Apr 20, 07:36 UTC | 9h 29m |
| 2026-04-19 | UAL879 | LHR → IAH | Apr 19, 09:10 UTC | Apr 19, 19:05 UTC | 9h 55m |
| 2026-04-18 | UAL880 | IAH → LHR | Apr 18, 22:35 UTC | Apr 19, 01:05 UTC | 2h 30m |
| 2026-04-18 | UAL880 | IAH → LHR | Apr 18, 22:32 UTC | Apr 19, 06:41 UTC | 8h 9m |
| 2026-04-18 | UAL879 | LHR → IAH | Apr 18, 09:15 UTC | Apr 18, 19:15 UTC | 10h 0m |
| 2026-04-18 | UAL879 | LHR → IAH | Apr 18, 09:25 UTC | Apr 18, 19:15 UTC | 9h 50m |
| 2026-04-18 | UAL918 | IAD → LHR | Apr 18, 05:25 UTC | Apr 18, 06:05 UTC | 40m |
| 2026-04-18 | UAL918 | IAD → LHR | Apr 18, 04:45 UTC | Apr 18, 06:05 UTC | 1h 20m |
| 2026-04-18 | UAL918 | IAD → LHR | Apr 18, 04:40 UTC | Apr 18, 05:20 UTC | 40m |
| 2026-04-18 | UAL918 | IAD → LHR | Apr 18, 01:25 UTC | Apr 18, 01:35 UTC | 10m |
| 2026-04-17 | UAL918 | IAD → LHR | Apr 17, 23:36 UTC | Apr 18, 06:00 UTC | 6h 24m |
| 2026-04-13 | UAL804 | - | Apr 13, 16:15 UTC | Apr 13, 19:05 UTC | 2h 50m |
| 2026-04-13 | UAL804 | - | Apr 13, 15:50 UTC | Apr 13, 19:05 UTC | 3h 15m |
| 2026-04-13 | UAL804 | - | Apr 13, 14:45 UTC | Apr 13, 16:15 UTC | 1h 30m |
| 2026-04-13 | UAL804 | - | Apr 13, 07:55 UTC | Apr 13, 08:05 UTC | 10m |
| 2026-04-13 | UAL804 | - | Apr 13, 07:30 UTC | Apr 13, 08:05 UTC | 35m |
| 2026-04-13 | UAL875 | SFO → HND | Apr 13, 04:20 UTC | Apr 13, 04:50 UTC | 30m |
| 2026-04-13 | UAL875 | SFO → HND | Apr 13, 03:55 UTC | Apr 13, 04:50 UTC | 55m |
| 2026-04-13 | UAL875 | SFO → HND | Apr 13, 03:40 UTC | Apr 13, 04:15 UTC | 35m |
| 2026-04-12 | UAL875 | SFO → HND | Apr 12, 17:55 UTC | Apr 13, 04:30 UTC | 10h 35m |
About Mode-S
A Mode-S transponder code (also called an "ICAO 24-bit address" or "hex code") is a 6-character hexadecimal identifier permanently assigned to an aircraft when it's first registered. Unlike callsigns (which change with each flight) or registrations (which can change if an aircraft is sold internationally), the Mode-S address stays with the airframe for the life of the aircraft in that country.
Every ADS-B transmission from an aircraft includes its Mode-S address, making it the most reliable way to identify a specific airframe. Flight-tracking services like Apparatus use the Mode-S address as the primary key for tying position broadcasts, callsigns, and ownership records together.
Prefer a tail-number view? See the N27015 page for operator, model, and routing details .